Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a4714aa8ddbd1bb…

MALICIOUS

PDF

84.0 KB Created: 2021-10-22 11:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: aa6bae7e4a13c658c6f887efb6fbc764 SHA-1: c57ff12e6be28761668f190b0236791c5606673a SHA-256: 6a4714aa8ddbd1bb6cb73e13e7398c0b651c05cc4eb6afcbc6f4641521bd53c2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several links pointing to compromised CMS upload storage and disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the linked URLs suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://sh-ruiyangcpa.com/userfiles/file/2021-9///2021927617266599.pdf In PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614daa1c3f565---27694776581.pdfIn PDF document text
    • https://znalac.com/userfiles/file/10463952845.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132eeb235505---gelukulobajogumopafepov.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20211008031557.pdfIn PDF document text
    • http://jujucuisine.com/userfiles/file/4810579529.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/52383606852.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/15370862938.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/38132152519.pdfIn PDF document text
    • http://wingtsunkungfu.ro/imagini_ws/nonudizozuba.pdfIn PDF document text
    • https://music-group-store.com/upload/files/desafitelutibixowefaki.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/fimifetabetumex.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/45380937534.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/gabupilepazimidasepa.pdfIn PDF document text
    • https://kvkumariajnkvv.org/singhania/downloads/file/magodarebijiwulilelepojiv.pdfIn PDF document text
    • http://cnkls.com/userfiles/file/1633167233.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1616ad89ddc075---xuviminadinoparu.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/kifenimofojun.pdfIn PDF document text
    • http://ovstav.cz/app/webroot/files/files/gisafigogureraganega.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/34794936535.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/lalisazuvej.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/8816183371.pdfIn PDF document text
    • https://vasantviharproperties.com/userfiles/file/52115717342.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/14663831582.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/rapagutetorebotesoz.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/tgwjJlsMqHc/uplcv?utm_term=avengers+in+order+of+moviesPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e21b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21B 10440 bytes
SHA-256: fe9a1b64a1e09e250864a312ea8aee5a0fffde8ed8d68bba7cd8073a21a7eb00
font_01_sfnt_off0000f990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF990 18584 bytes
SHA-256: fc55a7435840ab05535f0d4c8b994946e507fe0eb1d0d8fc28f77735be7ede1c
font_02_sfnt_off00012a2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1